The inventive concepts generally relate to electronic devices, such as semiconductor devices. More particularly, the inventive concepts relate to electrostatic discharge (ESD) protection devices and to methods of fabricating the same.
Electrostatic discharge (ESD) can result from a variety of factors, such as exposure to an electrostatic field or direct contact with an item carrying electrostatic charge. ESD can be particularly damaging to electronic devices, such as semiconductor devices. For example, when a semiconductor device including metal oxide semiconductor (MOS) transistors experiences electrostatic discharge (ESD), the device may be subjected to an instantaneous voltage of 3000V or more, thus damaging a gate insulating layer of the MOS transistors. The resultant partial or complete breakdown of the gate insulating layer can adversely impact the reliability and/or operability of the semiconductor device.
An ESD protection circuit may be utilized in an attempt to prevent ESD-related damage. For example, an ESD protection circuit may be incorporated in a semiconductor device to avoid breakdowns in gate insulating layers resulting from ESD. Generally, ESD protection characteristics are improved as the size of the ESD protection circuit is increased. However, large ESD protection circuits run counter to the industry trend of increased circuit integration and decreased chip size.